From 61b1e3b563d3b8123d77121019a2cb86a50e8fe4 Mon Sep 17 00:00:00 2001
From: Adrian Johnson <ajohnson@redneon.com>
Date: Mon, 4 Nov 2013 20:58:23 +1030
Subject: [PATCH 06/11] PDFDoc: compress decrypted streams

---
 poppler/PDFDoc.cc | 40 +++++++++++++++++++++++++---------------
 poppler/PDFDoc.h  |  3 ++-
 poppler/Stream.h  | 23 +++++++++++++++++++++++
 3 files changed, 50 insertions(+), 16 deletions(-)

diff --git a/poppler/PDFDoc.cc b/poppler/PDFDoc.cc
index ab02eda..6a497ff 100644
--- a/poppler/PDFDoc.cc
+++ b/poppler/PDFDoc.cc
@@ -77,6 +77,7 @@
 #endif
 #include "PDFDoc.h"
 #include "Hints.h"
+#include "DeflateStream.h"
 
 #if MULTITHREADED
 #  define pdfdocLocker()   MutexLocker locker(&mutex)
@@ -990,13 +991,23 @@ void PDFDoc::writeDictionnary (Dict* dict, OutStream* outStr, XRef *xRef, Guint
   outStr->printf(">> ");
 }
 
-void PDFDoc::writeStream (Stream* str, OutStream* outStr)
+// Find the length of this stream after compressing with Deflate
+Goffset PDFDoc::getFlateStreamLength (Stream* str)
+{
+  NullOutStream nullStr;
+  DeflateStream deflateStr(&nullStr);
+  deflateStr.copyStream(str);
+  deflateStr.close();
+  return nullStr.getNumBytesWritten();
+}
+
+// Write stream using Deflate compression
+void PDFDoc::writeFlateStream (Stream* str, OutStream* outStr)
 {
   outStr->printf("stream\r\n");
-  str->reset();
-  for (int c=str->getChar(); c!= EOF; c=str->getChar()) {
-    outStr->printf("%c", c);  
-  }
+  DeflateStream deflateStr(outStr);
+  deflateStr.copyStream(str);
+  deflateStr.close();
   outStr->printf("\r\nendstream\r\n");
 }
 
@@ -1093,8 +1104,7 @@ void PDFDoc::writeObject (Object* obj, OutStream* outStr, XRef *xRef, Guint numO
                           CryptAlgorithm encAlgorithm, int keyLength, int objNum, int objGen)
 {
   Array *array;
-  Object obj1;
-  Goffset tmp;
+  Object obj1, obj2;
 
   switch (obj->getType()) {
     case objBool:
@@ -1194,13 +1204,7 @@ void PDFDoc::writeObject (Object* obj, OutStream* outStr, XRef *xRef, Guint numO
             stream = encStream;
           }
 
-          stream->reset();
-          //recalculate stream length
-          tmp = 0;
-          for (int c=stream->getChar(); c!=EOF; c=stream->getChar()) {
-            tmp++;
-          }
-          obj1.initInt64(tmp);
+          obj1.initInt64(getFlateStreamLength(stream));
           stream->getDict()->set("Length", &obj1);
 
           //Remove Stream encoding
@@ -1209,8 +1213,14 @@ void PDFDoc::writeObject (Object* obj, OutStream* outStr, XRef *xRef, Guint numO
           }
           stream->getDict()->remove("DecodeParms");
 
+	  // Set FlateDecode filter
+          if (DeflateStream::enabled()) {
+            obj2.initName("FlateDecode");
+            stream->getDict()->set("Filter", &obj2);
+          }
+
           writeDictionnary (stream->getDict(),outStr, xRef, numOffset, fileKey, encAlgorithm, keyLength, objNum, objGen);
-          writeStream (stream,outStr);
+          writeFlateStream (stream,outStr);
           delete encStream;
           obj1.free();
         } else {
diff --git a/poppler/PDFDoc.h b/poppler/PDFDoc.h
index 0fa157b..0184f7e 100644
--- a/poppler/PDFDoc.h
+++ b/poppler/PDFDoc.h
@@ -279,7 +279,8 @@ private:
   void writeDictionnary (Dict* dict, OutStream* outStr, Guchar *fileKey, CryptAlgorithm encAlgorithm,
                          int keyLength, int objNum, int objGen)
   { writeDictionnary(dict, outStr, getXRef(), 0, fileKey, encAlgorithm, keyLength, objNum, objGen); }
-  static void writeStream (Stream* str, OutStream* outStr);
+  static Goffset getFlateStreamLength (Stream* str);
+  static void writeFlateStream (Stream* str, OutStream* outStr);
   static void writeRawStream (Stream* str, OutStream* outStr);
   void writeXRefTableTrailer (Goffset uxrefOffset, XRef *uxref, GBool writeAllEntries,
                               int uxrefSize, OutStream* outStr, GBool incrUpdate);
diff --git a/poppler/Stream.h b/poppler/Stream.h
index 925b951..dd276f4 100644
--- a/poppler/Stream.h
+++ b/poppler/Stream.h
@@ -321,6 +321,29 @@ private:
 
 #endif
 
+
+//------------------------------------------------------------------------
+// NullOutStream
+//------------------------------------------------------------------------
+class NullOutStream : public OutStream {
+public:
+  NullOutStream () { count = 0; }
+
+  ~NullOutStream () {};
+
+  Goffset getNumBytesWritten() { return count; }
+
+  void close() {}
+
+  Goffset getPos() { return 0; }
+
+  void write (const Guchar *data, long length) { count += length; }
+
+private:
+  Goffset count;
+};
+
+
 //------------------------------------------------------------------------
 // BaseStream
 //
-- 
1.8.3.2